Siemens SINUMERIK 808D User Manual page 197

See the following illustration for _AS1/_AS2:
In the case of central (G40), approach and retraction is only possible along a straight line.
_FF3 (retraction feedrate)
Use the parameter _FF3 to define a retraction feedrate for intermediate positions in the plane (in the open) if the
intermediate motions are to be carried out with feedrate (G01). If no feedrate value is programmed, the intermediate motions
with G01 are carried out at surface feedrate.
N o te
A tool compensation must be programmed before the cycle is called. Otherwise, the cycle is aborted and alarm 61000 "No
tool compensation active" is output.
Programming and Operating Manual (Milling)
197
6FC5398-4DP10-0BA6, 09/2017